Gpu not compatible with motherboard?

[delsaber]

Ive been trying to build my friends computer for a few days now and today we have discovered its the graphics card that is the issue.

The GPU works on this mobo (my mobo)

http://www.gigabyte.com/products/product-page.aspx?pid=3239#ov

Th gpu failed to work on these MOBOs;

http://www.gigabyte.com/products/product-page.aspx?pid=4150#ov

http://uk.msi.com/product/mb/B75MA-P45.html

Now I was told it could be due to the variation between pci-e 2.0 and pci-e 3.0 but I thought pci-e 3.0 would support this 2.1 GPU?


Any ideas on why this wont work on the newer motherboards would be great help!

 

[o1die]

What is your power supply make, model number, and 12v rail rating in amps?

 

[delsaber]

We originally had a 530w be quiet psu linked below;

http://www.aria.co.uk/Products/Components/Power+Supplies+-+PSUs/Non-Modular+650W+or+less/530W+be+quiet%21+PURE+POWER+L7+80PLUS+Power+Supply+?productId=49506

We then went and got a bigger 750w ocz linked below;

http://www.pcworld.co.uk/gbuk/ocz-zs750w-uk-zx-series-atx-psu-750w-11342078-pdt.html?srcid=867&cmpid=comp~Google~~11342078&istCompanyId=9a35962d-802d-4e67-9721-0a3328ca1f02&istItemId=iqxwaqpt&istBid=t